Apparatus for driving anchoring devices into hard receiving materials

ABSTRACT

AN APPARATUS FOR DRIVING ANCHORING DEVICES INTO HARD RECEIVING MATERIAL, SUCH AS CONCRETE, COMPRISES POSITIONING A MASS SUCH THT IT SURROUNDS THE DRIVE-IN POINT AND SUPORTS THE RECEIVING MATERIAL DURING THE DRIVING PROCESS. THE MASS IS ADVANTAGEOUSLY URGED AGAINST THE RECEIVING MATERIAL SO THAT IT WILL BE UNIFORMLY POSITIONED THERON TO PREVENT THE CRACKING OR NICKLING OF THE RECEIVING MATERIAL. THE APPARATUS FOR EFFECTING THIS INCLUDES A SETTING GUN HAVING A RECIPROCATING BARREL THIS INCLUDES A SETTING ANCHORING ELEMENT INTO THE CONCRETE. ASSOCITED WITH OR DIRECTLY CONNECTED TO THE BARREL IS THE MASS. THE MASS SURROUNDS THE CONCRETE AT THE LOCATION OF THE PLACEMENT OF THE ANCHORING ELEMENT AND IS ADVANTAGEOUSLY PROVIDED WITH A CENTRAL OPENING TO PERMIT THE DRIVE PISTON TO MOVETHERETH ROUGH AND TO DRIVE THE ANCHORING ELEMENT INTO THE CONCRETE AT SUCH LOCATION. ANOTHER EMBODIMENT INCLUDES A WIDENED FLANGE PORTION SURROUNDING THE BARREL AND WHICH HAS AS AN INTERNAL LEDGE PORTION WHICH SUPPORTS THE MASS BUT PREVENTS IT FROM BECOMING DISASSOCIATED WITH THE BARREL. THE MASS IS MOUNTED SO THAT IT IS URGED IN A CONTACTING DIRECTION TOWARD THE RECEIVING MATERIAL BY A COIL SPRING CONTAINED WITHIN THE FLANGE EXTENSION.

Sept. 20, 1971 A. RITTER 3,605,129

' APPARATUS FOR DRIVING ANCHORING' DEVICES INTO HARD RECEIVING MATERIALS Filed Jan, 21, 1969 2Sheets-$ho0t 1 lwmvma 4.00M ,e/rree ,flqgw J a A 77 0044275 A. 'RITTER 3,606,129 APPARATUS FOR DRIVING ANCHORING DEVICES INTO HARD RECEIVING MATERIALS Sept. 20,1911

A TTDENEYJ' United States Patent Patented Sept. 20, 1971 3,606,129 APPARATUS FOR DRIVING ANCHORING DEVICES INTO HARD RECEIVING MATERIALS Adolf Ritter', Mauren, Liechtenstein, assignor to Hilti Aktiengesellschaft, Schaan, Liechtenstein Filed Jan. 21, 1969, Ser. No. 792,517 Claims priority, application Germany, Apr. 3, 1968, P 17 03 117.3 Int. Cl. B25c 1/18 U.S. Cl. 227-11 8 Claims ABSTRACT OF THE DISCLOSURE An apparatus for driving anchoring devices into hard receiving material, such as concrete, comprises positioning a mass such that it surrounds the drive-in point and supports the receiving material during the driving process. The mass is advantageously urged against the receiving material so that it will be uniformly positioned thereon to prevent the cracking or nicking of the receiving material. The apparatus for effecting this includes a setting gun having a reciprocating barrel member for driving the anchoring element into the concrete. Associated with or directly connected to the barrel is the mass. The mass surrounds the concrete at the location of the placement of the anchoring element and is advantageously provided with a central opening to permit the drive piston to movetherethrough and to drive the anchoring element intothe concrete at such location. Another embodiment includes a widened flange portion surrounding the barrel and which has an internal ledge portion which supports the mass but prevents it from becoming disassociated with the barrel. The mass is mounted so that it is urged in a contacting direction toward the receiving material by a coil spring contained within the flange extension.

SUMMARY OF THE INVENTION This invention relates, in general, to an apparatus for driving anchoring elements into a hard receiving material and, in particular, to a new and useful apparatus for driving an anchoring element into a concrete receiving material which includes a mass member which is adapted to be positioned in contact with the receiving material and to surround the anchoring element as it is driven into the material.

When small sized anchoring elements such as nails, bolts and similar items are driven into a hard receiving material such as concrete, there is the tendency for the concrete to become cracked or nicked in the surrounding area. When such cracks or nicks are produced, they reduce the retention force holding the bolt in the receiving material and they also cause the blemishing of the surface of the receiving concrete. The nicking is caused when the anchoring element is driven under a great force into the receiving material and as it penetrates the concrete it will displace it laterally and counter to the driving direction. The result is that the stresses produced will lead to the nicking of the concrete around the driving-in point.

In accordance with the present invention, there is provided an apparatus for avoiding the nicking of the concrete which includes the positioning of a mass around the drive-in point and in contact with the receiving material such that it absorbs the driving forces and prevents the occurrence of nicks or cracks. The invention is based on the realization that the forces tending to cause the rupture of the concrete must be at least partly damped or abolished by counteracting forces which prevent nicking. In accordance with the invention these pressure forces are provided by the inertia of a mass which is arranged to cover the receiving material around the driving-in point. The sides of the mass to 'be used depends on the velocity of the driving tool during the driving operation. In addition, the form of the anchoring element influences the size of the mass which must be employed. Naturally, with an increase of the shaft diameter of the anchoring element which is to be driven into the concrete, there will be an increase in the mass which is employed.

Experiments have shown, for example, that when using a thrust piston setting tool, such a tool will be supported at its outer end or tip at the location of the receiving material before the driving operation is started. Such a tool may include a barrel and a surrounding flange, for example, Which would apply a mass of from 400 to 600 grams which is suflicient to prevent most nicks which would occur without the use of such a mass. By making the mass serving to support the receiving. material still larger, a further reduction of the nicks is possible. A mass greater than 600 grams will be used only if the more difficult handling inherent in its use is acceptable. It is possible, even with a thrust piston driving tool or setting tool, to use a mass which is less than 400 grams if the handling of the tool is a principal factor to be considered and a larger number of nicks can be accepted with the operation of the tool. It is also true that with those setting devices, which employ a driving piston which operates at a very high velocity, there will be a small number of nicks that will occur so that a smaller mass will be sufficient to reduce these. nicks.

There is extensive freedom of choice in respect to the form of the mass, but the mass should have an adequate bore for the passage of the attaching device driving element and this bore is advantageously arranged in the center of the mass. When using a tool having a drive piston, which reciprocates toward the target material, the diameter of the bore should be selected so that the front portion of the piston can pass through the bore. In order to sufficiently protect the receiving material surrounding the drive-in point, the diameter of a cylindrically-formed mass should be at least 40 mm. when the center is provided with a bore for accommodating the drive piston. When the anchoring element is provided with a thick shank the diameter should be selected at a somewhat larger range from 60 to 70 mm., for example.

In principle, it is possible, according to the invention, first to place the mass on the receiving material and to position the driving utensil. For easier handling, the support mass is connected with the end of the driving tool and advantageously may be carried within a flanged extension or protection cap surrounding the tool barrel. The cap advantageously provides a guiding support for the mass and retains it in position in association with and surrounding the barrel. The mass is advantageously mounted so that it may be moved radially and axially at least within a certain range. This permits the mass to be moved so that it will lie flat and evenly on the receiving material. The cap carrying the mass may advantageously be of a wider diameter and shaped so that it too may abut against the face of the receiving material but at a spaced location from the centrally located mass. By providing a radial play for the support mass, it is assured that the receiving material at locations immediately surrounding the drive-in point will be equally loaded. It is also advantageous to provide a biasing means to bias the mass in an axial direction toward engagement with the receiving material to ensure that it engages over the entire surrounding area. The bore which is designed to accommodate the drive piston of the setting tool is advantageously made large enough to also accommodate the surrounding barrel of the tool with play so that the mass may adapt itself to the nature of the receiving material.

In another embodiment of the construction, the driving tool is advantageously provided with a mass which includes preferably an annular area formed by a hose or flexible element embedded in the contact end face of the mass and which is adapted to contact the receiving material. The flexible element is advantageously filled with a sand or an incompressible molding composition or a flexible incompressible material to permit it to be pressed tightly against the receiving material. The flexible hose is filled with a material which will conform to the unevenness of the receiving material and compensate for any such unevenness, so that the forces acting on the support mass and the receiving material will be transmitted as directly as possible. For this purpose, a rubber pad may be employed which will have somewhat less effect than the flexible hose tfilled with a sand material, for example.

In a preferred form of driving tool construction, the end of the tool is provided with a bell-shaped flange or protection cap having an internal annular ledge member or washer. The cap is engaged on the housing of the tool through a bayonet lock formation. The mass is supported on the internal ledge so that a shoulder portion thereof rests on the top of the ledge and will not be dislodged from the tool. A coil spring is compressed between the interior of the cap and the interior top surface of the mass to urge the mass in a direction. to engage the receiving material.

Accordingly, it is an object of the invention to provide an arrangement for driving anchoring elements into concrete which includes positioning a supporting mass on the concrete material at a location around the driving-in point and then driving the material into the receiving material while the mass is held closely against the material.

A furtherobject of the invention is to provide a setting tool for driving anchoring elements into a hard receiving material such as concrete which includes a reciprocating driving piston for moving an anchoring element rapidlly into the receiving material, and a mass, having a bore through which the driving piston may move, positioned around the setting tool at the end thereof; the mass having a contact surface which is adapted to engage the receiving material around the drive-in point.

A further object of the invention is to provide a setting tool which includes a barrel having a drive piston slidable therein for driving an anchoring element into a receiving material, a protection cap positioned around the barrel adjacent its opened end and a mass member carried within the cap and adapted to be pressed against the receiving material around the barrel.

A further object of the invention is to provide a setting tool which includes a mass for supporting the receiving material into which an anchoring element is adapted to be driven, the mass being associated with the setting tool but being mounted for axial and radial play and advantageously including, for example, a surface which is resilient and adapted to conform to the receiving material surface and which resilient surface advantageously includes a material such as sand to facilitate the positioning thereof.

A further object of the invention is to provide an anchoring device which is simple in design, rugged in construction and economical to manufacture.

The various features of novelty which characterize the invention are pointed out with particularity in the claims annexed to and forming a part of this specification. For a better understanding of the invention, its operating advantages and specific objects attained by its use, reference should be had to the accompanying drawings and descriptive matter in which there are illustrated and described preferred embodiments of the invention.

4 BRIEF DESCRIPTION OF THE DRAWINGS In the drawings:

FIG. 1 is a partial sectional view of a setting tool in a position at which it has driven an anchoring element into a concrete material, and constructed in accordance with the invention;

FIG. 2 is a view similar to FIG. 1, of another embodiment of the invention; and

FIG. 3 is a view similar to FIG. 1, of still another embodiment of the invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to the drawings, in particular, the invention embodied therein in FIG. 1 comprises a setting tool generally designated 3 which is shown in position over a hard receiving material such as concrete 2 after it has driven an anchoring element 1 into this material. The setting tool 3 includes a barrel 3a and a drive piston 3b is slideable in the barrel. The drive piston 311 includes a recess 3c at its outer or driving end for accommodating the upper end of an anchoring device 1 which in this instance is a bolt. The drive piston 3b is adapted to be moved rapidly such as by force of a hammer blow or by the force of an explosive charge to drive the bolt 1 into the receiving material 2.

In accordance with the invention, a mass generally designated 4 of about 6 00 grams is placed between the setting tool 3 and the receiving material '2. In accordance with this embodiment, the mass 4 is provided with a small diameter bore 4a adjacent the receiving material 2 which is of a size to accommodate the drive piston 3b to permit it to move downwardly to the position indicated during the driving operation. The mass 4 also includes a larger diameter bore 4b opening to the opposite face which forms a ledge 40 at its junction with the smaller diameter bore 4a upon which the end of the barrel 3c rests in both the initial and the final driving operation.

The barrel 3a may thus be pressed against the mass 4 to hold it against the receiving material 2 before the anchoring device 1 is driven into the material. The concrete of the material 2 is displaced during the driving of the bolt 1 and it will accelerate insofar as it gives way in a direction counter to the driving direction. The mass 4 which has a high inertia opposes the compressive forces which are produced by this movement. Because of the inertia of the mass any nicking of the concrete is prevented or at least a major portion of the nicking which might occur is lessened. It is of advantage for the best mode of operation if the mass does not participate in the movement of the setting tool in the direction of the arrow f during its reaction with the receiving material 2.

In the embodiment indicated in FIG. 2, there is provided a setting tool generally designated 3' which is of a type which, for example, may be operated by a trigger construction (not shown) to detonate an explosive charge to drive a piston member 19 which is slidable in a barrel 17. The barrel 17 is surrounded by a housing tube 11 which terminates at a spaced location from the driving end 17a of the barrel 17.

In accordance with the invention, a bell-shaped member or protection cap generally designated 12 is engaged around the lower end of the housing tube 1&1 and is arranged around the locking ring 18 thereon which is connected through the provision of a bayonet-type joint 10. The protection cap 12 has an annular end edge 12a which is adapted to abut against the receiving material.

In accordance with a further feature of the invention, the interior of the bell-shaped member 12 is provided with a ring or washer 13 which is welded at a spaced location from the end 1 20 and provides an abutment or a shoulder 14a for supporting a mass 14 which is captured within the protection cap 12. The supporting mass 14 is provided with a central bore 15 of a size to accommodate the barrel 1'7 and it maybe freely moved axially along the barrel within the limits controlled by the shoulder abutment 14a. The support mass \14 is loaded in a direction toward the receiving material by a compression spring 16 which is disposed between the top end thereof and the lower end of the tubular housing 11.

A feature of the construction of FIG. 2 is that the mass 14 is supported so that it may be axially and radially displaced within limits so that it may be positioned to rest directly against the receiving material during the driving operation. The spring holds the mass in position against the receiving material during the driving operation and prevents it from being lifted off the surface thereof by the reaction forces. The construction also permits adaptation of the mass to the surface conditions of the receiving material and the spring will permit the mass to move to accommodate any unevenness of the receiving material 2. This construction is particularly useful for working on constructional elements which are arranged over the head of the operator since the spring will insure that the mass will be moved upwardly against the material when the gun is positioned upwardly for firing.

In the embodiment indicated in FIG. 3, there is provided a setting tool generally designated 3 which includes a barrel member 17' which is surrounded by a tubular housing 11' and in this embodiment a protective cap 12 is advantageously secured to the lower end of the housing 11' over a lock ring 18' which is connected to the end of the barrel through the provision of a bayonet-type joint In this construction, a mass 1 4' is employed which includes an end face having a recess which accommodates a flexible tubular member or hose 20 which is filled with a material 21, for example, sand which provides a certain flexibility of the end surface of the tube to facilitate the tightpositioning thereof against the receiving material. In addition, a direct transmission of the forces acting from the support mass :14 to the receiving material 2 is possible. The material of the tube or hose 20 may be, for example, leather or a resistant plastic foil.

What is claimed is:

1. An apparatus for driving an anchoring element such as a bolt, nail and similar device into a hard receiving material such as concrete, comprising a driving tool including a barrel, having an open end adapted to be directed against the receiving material, a drive piston slidable in said barrel and movable toward the open end thereof to drive an anchoring element into the receiving material, a protective cap connected to said barrel and extending around the outer end thereof adjacent its opened end, and a mass carried by said protective cap and having a bore through which said barrel is adapted to extend, said mass being mounted for axial and radial movement within said protective cap.

2. An apparatus, according to claim 1, wherein said mass projects outwardly beyond the end of said protective cap, said cap having an edge defining an annular surface surrounding said mass which is adapted to abut against the receiving material when the mass is moved backwardly as it is pressed against the receiving material.

3. An apparatus, according to claim 2, including spring means for biasing said mass in a direction toward the opened end of said cap to engage the receiving material.

4. An apparatus, according to claim 1, wherein said mass includes a receiving material contacting surface having a flexible member thereon filled with a flexible incompressible material.

5. An apparatus, according to claim 1, wherein said protection cap is substantially bell-shaped and includes an interior annular member having a central opening through which said mass extends, said annular member defining an abutment, said mass having a shoulder adapted to be retained by the abutment to prevent withdrawal of the mass from said cap.

6. An apparatus, according to claim 5, including means biasing said mass in a direction to cause said shoulder to engage over said abutment.

7. An apparatus, according to claim 5, wherein said protection cap is connected to said barrel by a bayonet joint.

8. An apparatus for driving an anchoring element, such as a nail, bolt and similar elements, into a hard receiving material, such as concrete, comprising a driving tool including a barrel having an open end arranged to be directed toward the surface of the receiving material into which the anchoring element is to be inserted, a driving piston movably displaceable within said barrel for driving an anchoring element from its open end into the receiving material, an annular shaped mass of high inertia material positioned on and encircling the end of said driving tool containing the open end of said barrel, said mass being shaped to be secured against the receiving material by said driving tool for opposing the forces produced when the anchoring element is driven into the receiving material for preventing nicking or spalling of the material, and for providing limited axial and radial play between said mass and said driving tool for proper engagement between said mass and the receiving material.

References Cited UNITED STATES PATENTS 2,780,810 2/ 1957 Catlin et a1. 227-9 2,956,283 10/1960 Temple et a1. 227-11 3,008,361 11/1961 Henning 227147X 3,115,637 12/1963 Elliott 22710 3,221,966 12/1965 Kopf et a1. 227-11 FOREIGN PATENTS 167,800 6/1956 Australia 227-11 GRANVILLE Y. CUSTER, 1a., Primary Examiner 

